Sealing of revolver firing chamber



April 25, 1961 D. B. SERGAY SEALING OF REVOLVER FIRING CHAMBER 2 Sheets-Sheet 1 Filed June 22, 1959 .rilil rlilfllil v! I! ATTORNEY v April 25, 1961 D. B. SERGAY SEALING 0F REVOLVER FIRING CHAMBER 2 Sheets-Sheet 2 Filed June 22, 1959 ATTORNEY 2,981,023 SEALING F REVOLVER FIRING CHAMBER Filed June 22, 1959, Ser. No. 821,816

2 Claims. (Cl. 42-59) This invention relates to sealing of gun firing chambers, and particularly those of the revolver type adapted for use with combustible case ammunition.

It is among the principal objects of the invention to improve the sealing of the firing chamber, and to provide such sealing at the ends thereof between the revolver drum and the adjacent surfaces of the gun barrel and anvil, respectively, in a manner uniquely adapting the gun for use of combustible case ammunition. While it is old to provide a seal between the anvil and its adjacent end of the revolver drum, 1 have found that greatly improved component durability can be obtained by sealing the gun barrel end of the firing chamber, and that such scaling is particularly effective when the sealing means is in the form of an annular ring or sleeve having extended skirts so arranged as to expand against the surfaces of the parts to be sealed when acted upon by the firing pressure of the gases.

The means by which these and other objects and advantages are obtained will be more readily understood from the following description of the invention, having reference to the drawings illustrating three embodiments thereof, wherein:

Figure l is a side view of a portion of a revolver type gun, with portions broken away and showing the firing chamber to illustrate one embodiment of my improved sealing arrangement.

Figure 2 is an enlarged fragmentary view of the firing chamber of Figure 1.

Figure 3 is a further enlarged perspective view of one of the sealing rings employed in the chamber of Figure 2.

Figures 4 and 5 are views similar to Figure 2, but showing respectively different embodiments of the invention.

Referring now in detail to the drawings, the revolver type gun shown in Figure 1 includes a stock 1 and handle 2 by which is supported an elongated frame 3. Fixed within the frame 3 in conventional manner is a gun barrel 4 and a firing anvil 5 spaced from the rear end or breech face 6 of the barrel. Mounted for rotation in the frame 3 between the anvil and the breech face of the barrel is a movable member or drum 7 having the usual plurality of openings or firing chambers extending therethrough and spaced circumferentially about the drum axis, only one of which chambers is shown and need be described since they are identical.

As more clearly shown in Figure 2, the firing chamber 8 is in the form of a cylindrical opening extending lengthwise through the drum 7 and forms a receptacle for one round of ammunition designated generally by the numeral 9. As conventional in revolver type weapons, the ammunition round 9 is inserted into the chamber 8 prior to rotation of the drum to index the chamber 8 into alignment with the bore 10 of the barrel, there being suitable mechanism (not shown) for effecting such indexing of the drum 7 and for charging each such chamber with ammunition prior to indexing it into such position of alignment with the barrel bore. When thus aligned the an- United States Patent 0 ice vil 5 forms a closure for the rear or opposite end of the chamber 8.

The particular ammunition 9 shown comprises a projectile 11 Within a sabot 12 of plastic material, and a propellant section comprising a casing 13 cf combustible material and filled with conventional propellant material such as ball powder :19. Between the sabot 12 and the combustible case 13 is a piston or gas check 14 in the form of a plurality of rigid disks of aluminum or other stiif material to distribute the firing gas pressure over the rearward ends of the sabot and the projectile 11. Ignition of the propellant is by electrical induction, being an igniter or primer in the form of a closed loop of wire 15 which is mounted in the combustible base 16 of the casing and functions as a transformer secondary winding. This prime loop is heated electrically during firing by inducing current to flow therethrou-gh when a primary winding 17 is energized from an external source such as a battery or magneto (not shown). The core 18 of this primary winding extends centrally through the anvil 5 and terminates flush with the firing chamber face thereof. Rifiing lands 20 are provided on the forward end of the chamber 8 which engage the plastic sabot 12 to impart spin thereto prior to its entering the barrel bore 10.

Sealing means are provided at each end of the chamber 8 to prevent loss of firing gas pressure between the breech face 6, anvil 5 and the respective adjacent ends of the drum 7. As best shown in Figures 2 and 3, each of these sealing means is in the form of an annular ring of suitable material, such as hardened tool steel. Each is generally L-shaped in radial section, having a radially extending leg or main body portion 21 and an outer skirt formed by the axially extending leg portion 22. The forwardmost of these seal rings is disposed in a groove formed as a counterbore 23 at the barrel end of the chamber 8, and the rear seal ring is similarly located in a groove formed as a counterbore 24- facing the anvil 5. The axially extending skirts 22 of the seal rings closely fit the side walls of their respective counterbores and the radially extending legs 21 abut the barrel,

breech face 6 and the forward face of the anvil 5, respectively. By reason of the generally L-shaped section of these rings, their skirts 22 and radially extending legs 21 are adapted to expand under the propellant gas firing pressure into good tight sealing engagement with their supporting surfaces.

Thus, the propellant gases developed during combustion of the combustible case 8 and ball powder 19 react against both the leg 21 and skirt 22 of the rear seal, forcing them tightly against the anvil and the side walls of the counterbore 24, respectively. As the sabot 12 and projectile 11 pass into the bore 10 of the barrel, exposing the forward seal to the propellant gases, these gases similarly act against the leg 21 and lip 22, forcing them against the breech face 6 and the side walls of the counterbore 23.

In the modified sealing arrangement shown in Figure 4 the sealing rings are installed in grooves 25 and. 26 provided in the breech face 6 of the barrel and anvil 5, respectively, rather than in the chamber 8 of the drum. Also, the seal rings are in reverse relation to those previously described, in that the axially extending skirts 22 extend away from each other, rather than toward each other. As the result, the radially extending legs 21 thereof axially abut the end faces of the drum 7, and during firing of the gun the propellant gases act between axially opposite faces of the grooves radially extending legs 21 tightly into Expansion of the 22 against the radially outer by the gas pressure occurs similarly the rings and the 25, 26 to force the engagement with the drum end faces.

axially extending skirts walls of the grooves there as in the previously described embodiment. "Firing tests indicate that this sealing arrangement eliminates the occasional breech flashes that occur whenusing ring seals chambered in the drum as in the previously described embodiment. Another advantage is that, only two such seal rings are required in a revolver type weapon, since the seals do not index with the drum.

One disadvantage of the last described embodiment is that an unbalanced force on the drum exists from the instant the propellant gases strike the rear seal, until the departing bullet (sabot and projectile) allows the gases to reach the front seal. A further modification which prevents this is shown in Figure wherein the seals are in the form of sleeves 27, 28. In this arrangement'the chamber 29 is substantially larger in diameter than the bore of the barrel, and the seal sleeves bush or line the chamber 29 to the same diameter as the bore 10. The main body portion 30 of the rearseal is of uniform internal diameter and axially abuts at its rearward end with the anvil 5. At its forward end this sealing sleeve 28, is internally relieved to provide a forwardly extending skirt 31. Similarly, the main body of the forward sealing sleeve abuts the breech face of the barrel, and has its rearward end internally relieved to provide an axially extending skirt 32. As shown, the skirts 31 and 32 are axially spaced slightly from each other, whereby the combustion gasesreact over the entire cross-sectional area of the sleeves to force them tightly against the breech face 6 and anvil 5, respectively. Since'the application of this gas force occurs practically simultaneously upon firing of the ammunition, and since the resulting seal thrust is against the barrel and anvil rather than against the drum, no appreciable unbalanced force is applied to the drum during firing.

While only three preferred embodiments of the invention have been disclosed, it is appreciated that numerous minor changes in the construction and arrangement I of the parts may be made without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. In a revolver-type gun, a drum having a firing chamber extending longitudinally therethrough, a gun barrel axially adjacent one end ofthe drum and having a bore, said drum being rotatable to a position of alignment of said chamber with said bore, an anvil axially adjacent the opposite end of the drum and closing the chamber at said opposite end'when the drum is rotated to said position, said chamber being of larger diameter than said bore, and two axially adjacent annular sleeves lining the chamber, said sleeves each having its internal diameter substantially equal to the diameter of said bore and each having an axially extending skirt portion at its end inwardly of the chamber, said skirt portions being of greater internal diameter than the remainder of the sleeves and of the same ex'ternaldiameter, the opposite ends of said sleeves being in axialabutment with the barrel and anvil, respectively,

and the extended ends of said skirt portions being slightly spaced 'from each other, whereby the combustion gases developed in the chamber during firing of the gun react over the entire cross-sectional area of the sleeves for forcing them against the barrel and anvil.

2. The invention of claim 1, wherein said sleeve abutting the barrel is provided with rifling lands on its internal periphery.

References Cited in the file of this patent UNITED STATES PATENTS 2,790,353 Bird Apr. 30, 1957 2,835,171 Lyon May 20, 1958 2,889,654 Fever June 9, 1959 FOREIGN PATENTS 87,672 France 'Nov. 2, 1869 1,157,474 France May 29, 1958 

